RU2819873C1 - Mixture for producing foamed glass - Google Patents

Abstract

FIELD: various technological processes.

SUBSTANCE: invention relates to production of foamed structural heat-insulating material which can be used in construction industry. Mixture for foamed glass is prepared by combined grinding of scrap glass, dusty wastes of electrometallurgical production and one of the following components: boric acid, industrial borax in a rotary vortex mill with the following ratio of components, wt.%: dusty wastes of metallurgical production from 40 to 70; dusty glass production wastes from 20 to 50; boric acid 5 or industrial borax 10. For the charge foaming, a foaming liquid in the form of a protein foaming agent is added to the jointly crushed components at rate of 165 ml per 1 kg of the dry mixture. Prepared charge is poured into mould, evenly distributed, placed into furnace, heated to temperature of 800 °C and held for 5 hours.

EFFECT: recycling glass scrap and dusty wastes of electrometallurgical production by using them in production of foamed glass.

1 cl, 2 tbl

Description

The invention relates to the field of building materials, namely the production of foam glass, and can be used in the construction industry to create foamed structural thermal insulation materials.

Known RF Patent 2051869 (C03C11/00) - a charge for producing foam glass including zeolite-containing tuff and a gas-forming agent based on silicon carbide, characterized in that, in order to reduce the foaming temperature and expand the raw material base, it additionally contains cullet and soda ash.

RF Patent 2487842 (C03C11) is known, which proposes the use of a charge of the following composition, wt.%: ground cullet - 75.0-90.0; diamond processing waste - 10.0-25.0. Diamond enrichment waste has the following composition, wt.%: serpentine 70.0; calcite 2.0; dolomite 28.0. The proposed technical solution allows us to resolve the issue of expanding the raw material base for producing foam glass.

Also known is RF Patent 2246457 (C03C11/00), which proposes the use of the following charge components, wt.%: glass cullet 58.5-64.5, apatite-nepheline ore enrichment waste 15.0-22.6, quartz 15.5- 17.2, gas generator 3.3-4.0. The use of the proposed charge makes it possible to reduce the density of the foam glass facing material by an average of 1.25 times and reduce its thermal conductivity by 1.27 times.

The proposed compositions make it possible to produce foam glass at temperatures from 900 to 1000°C, which allows the use of standard equipment used in foam glass production, but the specified temperature range is characterized by high energy consumption.

RF patent No. 2291125 (C03C11/00) was chosen as a prototype - a charge for producing foam glass, which includes cullet container glass and sugar production waste, which acts as a foaming agent under thermal influence on the prepared glass by joint grinding in a ball mill. The main difference between this technical solution and its analogues is the use of sugar production waste as a gas-forming substance, which makes it possible to obtain a material with good heat and sound insulation properties. The disadvantages of the prototype include the high temperature of heat treatment of the charge and the need for additional annealing of the resulting foam material, which affects the final cost.

As an analogue, patent No. RU 2575720 was chosen - a mixture for producing foam glass, which contains only glass cullet and galvanic production sludge. The main difference between this technical solution and its analogues is the use of galvanic production sludge as a gas-forming substance. The disadvantages of the analog include high water absorption and insufficiently high frost resistance for this category of materials.

The objective of the technical solution of the present invention is to develop a formulation for the composition of the charge for producing foamed glass thermal insulation material for structural purposes.

The technical result of the invention is the recycling of cullet and dusty waste from electrometallurgical production by using them in the production of foam glass. Dust-like waste from electrometallurgical production contains carbonates, oxides and silicates of metals with the following ratio of elements in terms of oxides, wt.%:

• Fe ₂ O ₃ - 55.4;

• CaO - 12.6;

• SiO ₂ - 5.9;

• Na ₂ O - 5.9;

• K ₂ O - 4.2;

• CO ₂ – 2.9;

• MgO - 2.8;

• ZnO - 2.1;

• SO ₃ - 1.7;

• MnO - 1.5;

• Cl - 0.4;

• Al ₂ O ₃ - 0.4;

• Cr ₂ O ₃ - 0.3;

• PbO - 0.1;

• CuO - 0.1;

• Other impurities - 3.7.

The problem is solved due to the fact that the charge for foam glass is prepared by joint grinding of cullet, dusty waste from electrometallurgical production and one of the following components: boric acid, technical borax in a rotary vortex mill. When exposed to heat, boron compounds pass into the foamed glass mass in the form of boron oxide, which significantly reduces the coefficient of thermal expansion, which allows the glass mass not to crack during sudden temperature changes

The charge for producing foam glass includes: cullet (including dusty waste from glass production), boric acid, dusty waste from electrometallurgical production in the following ratio, wt.%:

• dusty waste from metallurgical production – from 40 to 70;

• dusty waste from glass production – from 20 to 50;

• boric acid or technical borax – the rest.

To foam the mixture, a foaming liquid (for example, a protein foaming agent) is added to the jointly crushed components at the rate of 165 ml. per 1 kg of dry mixture.

The mixture prepared according to the method described above is poured into a prepared mold, distributed evenly, placed in an oven, heated to a temperature of 800°C and kept for 5 hours.

After heat treatment, the oven is turned off, and when closed, it cools to room temperature. After firing is completed, the mold is removed from the kiln, the resulting sample is removed from the mold, polished and stored.

This method can be illustrated with examples. For this purpose, the mixture compositions presented in Table 1 were prepared.

Table 1. Composition of the charge, wt.%

Components Example number 1 2 3 4 dusty waste from metallurgical production 65 55 70 45 dusty waste from glass production thirty 40 20 45 boric acid 5 5 0 0 Technical borax 0 0 10 10 TOTAL 100 100 100 100

The physical and mechanical properties of the material obtained after firing in comparison with the analogue and prototype are presented in Table 2.

Table 2. Characteristics of foam material.

Index Example number Analogue Prototype 1 2 3 4 water absorption,% 0.03 0.03 0.03 0.03 2.8 - compressive strength, MPa 2.24 2.47 1.98 3.51 2.9 1.1 thermal conductivity, W/m·S 0.067 0.120 0.070 0.031 0.042 0.055 frost resistance 83 86 81 95 58 -

The data given in Table 2 confirms that the resulting foam glass samples, prepared on the basis of the supplied mixture, correspond to the physical and chemical properties required for this class of materials. The resulting samples are at the level of the analogue and the prototype in thermal conductivity, significantly superior to the analogue in frost resistance and water absorption, and 2-3 times superior to the prototype in strength.

This mixture recipe for the production of foam glass allows us to solve the problem of recycling dusty waste from electrometallurgical production and cullet by producing foamed silicate thermal insulation material for structural purposes, which can be used in the construction industry to create foamed thermal insulation materials.

Claims (1)

A charge for producing foam glass, including cullet, waste from metallurgical production, a boron compound and a foaming agent, characterized in that it contains dust-like waste from electrometallurgical production, containing the following elements, wt.%: Fe ₂ O ₃ 55.4, CaO 12.6, SiO ₂ 5.9, Na ₂ O 5.9, K ₂ O 4.2, CO ₂ 2.9, 2.8, ZnO 2.1, SO ₃ 1.7, MnO 1.5, Cl 0.4, Al ₂ O ₃ 0.4, Cr ₂ O ₃ 0.3, PbO 0.1, CuO 0.1, other impurities 3.7, boric acid or commercial borax as a boron compound, and the charge contains components in the following ratio , wt.%: dusty waste from electrometallurgical production from 40 to 70, cullet from 20 to 50, boric acid 5 or technical borax 10, as well as a protein foaming agent in the form of a foaming liquid at the rate of 165 ml per 1 kg of dry mixture.